FAT: Directory bread error causes a kernel crash and reboot system

Question

I'am developing an embedded Linux DLNA server application based on turnkey server, I use a customized Linux system based on openwrt.

The problem is => if I unplug the USB hard disk while my DLNA server build the media database I got many times the following error :

FAT: Directory bread(block 2700948) failed

what causes a kernel crash and reboot system ? I want to know what is exactly the error mean ? and how can i prevent it ?

Answer 1

This error message is seen in function fs/fat/dir.c:fat__get_entry()

This error possibly occurred while trying to read a block = 2700948, due to some failure or corruption or disk error.

Going forward, I would recommend doing an {dosfsck,fsck.vfat} -nv -y /path/to/dev/ while the partition is unmounted. Also it would good idea to check your disk for any bad sectors.